"""
Copyright 2005 Allen B. Downey
This file contains an example program from The Little Book of
Semaphores, available from Green Tea Press, greenteapress.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see http://www.gnu.org/licenses/gpl.html
or write to the Free Software Foundation, Inc., 51 Franklin St,
Fifth Floor, Boston, MA 02110-1301 USA
"""
from threading_cleanup import *
class Shared:
def __init__(self, end=10):
self.counter = 0
self.end = end
self.array = [0]* self.end
self.mutex = Semaphore(1)
def child_code(shared):
while True:
shared.mutex.wait()
if shared.counter < shared.end:
shared.array[shared.counter] += 1
shared.counter += 1
shared.mutex.signal()
else:
shared.mutex.signal()
break
class Histogram(dict):
def __init__(self, seq=[]):
for item in seq:
self[item] = self.get(item, 0) + 1
shared = Shared(1000000)
children = [Thread(child_code, shared) for i in range(2)]
for child in children: child.join()
print Histogram(shared.array)